In a diversity of military and commercial situations, many aircraft are required to operate in the same space, for example, in landing areas, during formation flights, during air and ground re-fueling, and many more. Such situations could be potentially dangerous for human life and property, in case one aircraft hits one or more vehicles. The potential danger of collision characterized not only mid-air and ground air traffic but also on/in water and on-ground traffic. Therefore, many efforts in the art are aimed at avoiding collisions.
U.S. Pat. No. 6,531,978 discloses a mid-air collision avoidance system (MCAS) that employs the existing design of Traffic Alert and Collision Avoidance System (TCAS) as a module and seamlessly integrates it with a customized tactical module, which is capable of providing unique tactical avoidance guidance control and display. The tactical module handles all phases of a tactical mission, including formation flight (e.g., formation fall-in, arming formation flight, engaging formation flight following, and formation brake-away), and an air-refueling sequence (e.g., rendezvous, linkup, re-fueling, and disengaging air-refueling). The tactical module divides the air space around the aircraft into advisory, caution, and warning zones and for each provides display, tone and voice alerts to facilitate pop-up avoidance guidance commands. Military aircraft can thus effectively avoid mid-air and near mid air collision situations in all three different operation modes: air traffic control (ATC) management mode, tactical mode, and a mixed mode.
US Patent Application No. 20030004642 discloses a method and system for collision avoidance, carried by each aircraft, includes a miniature MEMS (Micro Electro Mechanical Systems) IMU (Inertial Measurement Unit), a miniature GPS (Global Positioning System) receiver, a display, a data link receiver/transmitter, and a central processing system. Each aircraft carries a GPS receiver coupled with a self-contained miniature IMU for uninterrupted state determination. The state information is shared with other aircraft over an RF (Radio Frequency) data link. An intelligent display shows the relative positions of the aircraft in the immediate vicinity of the host aircraft and issues voice and flashing warnings if a collision hazard exists.
U.S. Pat. No. 6,483,454 discloses collision avoidance systems (CAS) for groups of aircraft operating in close proximity, as during formation flights or cooperative missions. Fixed and rotary airfoil aircraft with separations of 30 feet to 5 miles, for example, participate in a local radio sub-net. An aircraft receiving CAS sub-net signals derives signal transit time values representing differences between send and receive times and which are used to derive data on inter-aircraft range and closing rate. With synchronized clocks, highly-accurate one-way ranging uses assigned time slots with predetermined sub-net time-of-day timing of transmissions. Round-trip ranging operates with less accurate time synchronization, and systems may operatively select between one-way and round-trip ranging. By exchange of range and closing rate data among aircraft, 3-D data for current three-dimensional location of aircraft enables evasive action determination. Data is thus made available for provision of audio and visual flight crew communications indicating alerts and warnings of impending collision danger and appropriate evasive action.
U.S. Pat. No. 5,587,904 disclosed an air combat monitoring system comprising a plurality of GPS receivers, mountable on a corresponding plurality of aircraft, an avionics monitor for monitoring the avionics systems of the plurality of aircraft, a memory for storing information received from the GPS receivers indicating the location of the plurality of aircraft and information received from the avionics monitor in order to provide a reviewable output indication of the performance of the plurality of aircraft and an information disseminator for communicating said information among said plurality of aircraft.
There is a need in the art for a collision avoidance system and method suitable for use in low-level flight and in low-velocity flight. There is a further need in the art for a collision avoidance system and method suitable for rotary-winged vehicles (e.g. helicopters). There is a further need in the art for a collision avoidance system and method for tight formation flight.